U.S. patent application number 12/384090 was filed with the patent office on 2010-09-30 for control circuit.
Invention is credited to Chia-Han Chan, Nan-Sheng Chang.
Application Number | 20100246084 12/384090 |
Document ID | / |
Family ID | 49933488 |
Filed Date | 2010-09-30 |
United States Patent
Application |
20100246084 |
Kind Code |
A1 |
Chan; Chia-Han ; et
al. |
September 30, 2010 |
Control circuit
Abstract
A control circuit includes a voltage-dividing resistor connected
to a voltage input terminal, at least one thermal breaker
series-connected between the voltage-dividing resistor and the
ground and disposed near one corresponding battery, and an output
terminal drawn forth from a connection location of the thermal
breaker and the voltage-dividing resistor and adapted to be
connected with a protective circuit. The thermal breaker breaks
according to the temperature of the corresponding battery, and then
the output terminal transmits different protective signals to the
protective circuit according to the working state of the thermal
breaker so as to make the protective circuit protect the battery
based on the protective signals. Therefore, the control circuit of
the present invention is relatively simpler and occupies a
relatively smaller space so that can meet the demand of both
miniaturization and low cost of electronic products.
Inventors: |
Chan; Chia-Han; (Tu-Cheng
City, TW) ; Chang; Nan-Sheng; (Tu-Cheng City,
TW) |
Correspondence
Address: |
ROSENBERG, KLEIN & LEE
3458 ELLICOTT CENTER DRIVE-SUITE 101
ELLICOTT CITY
MD
21043
US
|
Family ID: |
49933488 |
Appl. No.: |
12/384090 |
Filed: |
March 30, 2009 |
Current U.S.
Class: |
361/103 |
Current CPC
Class: |
H02H 5/047 20130101;
H02H 7/18 20130101 |
Class at
Publication: |
361/103 |
International
Class: |
H02H 5/04 20060101
H02H005/04 |
Claims
1. A control circuit adapted for transmitting protective signals to
a protective circuit so as to make the protective circuit protect a
battery based on the protective signals, the control circuit
comprising: a voltage-dividing resistor connected to a voltage
input terminal; at least one thermal breaker series-connected
between the voltage-dividing resistor and the ground, and disposed
near one corresponding battery, wherein the thermal breaker breaks
according to the predetermined temperature of the corresponding
battery; and an output terminal drawn forth from a connection
location of the thermal breaker and the voltage-dividing resistor,
the output terminal being adapted to be connected with the
protective circuit for transmitting different protective signals to
the protective circuit according to the working state of the
thermal breaker.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention generally relates to a control
circuit, and more particularly to a control circuit for protecting
a battery.
[0003] 2. The Related Art
[0004] At present, rechargeable batteries are widely used in many
electronic products as a power supply. Accordingly, it is necessary
to use a charging control circuit to charge/discharge the battery.
The charging control circuit includes a control circuit for
generating a protective signal according to a temperature of the
battery, and a protective circuit for controlling
charging/discharging of the battery based on the protective signal
from the control circuit so as to protect the battery from being
overcharged/over-discharged.
[0005] Referring to FIG. 2, a traditional control circuit 1'
includes a first thermistor T1, a second thermistor T2, a first
comparator U1, a second comparator U2 and an OUTPUT terminal. The
first comparator U1 is connected between the first thermistor T1
and the OUTPUT terminal, the second comparator U2 is connected
between the second thermistor T2 and the OUTPUT terminal, and the
OUTPUT terminal is connected with the protective circuit (not
shown). The first thermistor T1 and the second thermistor T2 are
respectively disposed near one rechargeable battery (not shown).
Under the normal condition, the OUTPUT terminal of the control
circuit 1' outputs a low level signal to the protective circuit. On
the contrary, if the temperature of any battery rises due to the
overcharging/over-discharging, then the OUTPUT terminal will output
a high level signal. For example, if the temperature of the battery
near the first thermistor T1 rises on account of the overcharging
or over-discharging, then the resistance of the first thermistor T1
will increase on account of the risen temperature so that causes
the voltage on the first thermistor T1 increased accordingly. As a
result, the first comparator U1 outputs a higher voltage that
causes the high level signal to be output by the OUTPUT terminal of
the control circuit 1'. Then, the protective circuit interrupts the
charging/discharging of the battery in the case where the high
level signal is received by the protective circuit so as to protect
the battery.
[0006] However, the foregoing control circuit 1' is so complicated
that occupies a relatively larger space and takes a relatively
higher cost. Therefore, it is difficult to meet the demand of both
miniaturization and low cost of the electronic products.
SUMMARY OF THE INVENTION
[0007] An object of the present invention is to provide a control
circuit adapted for transmitting protective signals to a protective
circuit so as to make the protective circuit protect a battery
based on the protective signals. The control circuit includes a
voltage-dividing resistor connected to a voltage input terminal, at
least one thermal breaker series-connected between the
voltage-dividing resistor and the ground and disposed near one
corresponding battery, and an output terminal drawn forth from a
connection location of the thermal breaker and the voltage-dividing
resistor and adapted to be connected with the protective circuit.
Wherein the thermal breaker can be broken according to the
temperature of the corresponding battery, and then the output
terminal transmits different protective signals to the protective
circuit according to the working state of the thermal breaker.
[0008] As described above, the control circuit of the present
invention protects the battery by way of the thermal breaker
instead of thermistors and comparators of the related art.
Therefore, the control circuit of the present invention is
relatively simpler and occupies a relatively smaller space so that
can meet the demand of both miniaturization and low cost of
electronic products.
BRIEF DESCRIPTION OF THE DRAWINGS
[0009] The present invention will be apparent to those skilled in
the art by reading the following description, with reference to the
attached drawings, in which:
[0010] FIG. 1 is a circuitry of a control circuit of the present
invention; and
[0011] FIG. 2 is a circuitry of a traditional control circuit.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0012] With reference to FIG. 1, a control circuit 1 according to
the present invention is shown. The control circuit 1 can generate
and transmit a protective signal to a protective circuit (not
shown) according to a temperature of a battery (not shown), wherein
the protective circuit can control charging/discharging of the
battery based on the protective signal from the control circuit so
as to protect the battery from being overcharged/over-discharged.
The control circuit 1 includes a first thermal breaker RT1, a
second thermal breaker RT2, a voltage-dividing resistor R and an
OUTPUT terminal. The second thermal breaker RT2 is series-connected
between the voltage-dividing resistor R and the first thermal
breaker RT1. The other terminal of the voltage-dividing resistor R
is connected to a voltage input terminal Vp, and the other terminal
of the first thermal breaker RT1 is connected to ground. The OUTPUT
terminal is drawn forth from a connection location of the second
thermal breaker RT2 and the voltage-dividing resistor R, and
further connected to the protective circuit so as to transmit the
protective signal thereto. The first thermal breaker RT1 and the
second thermal breaker RT2 are disposed near corresponding
batteries respectively.
[0013] In the embodiment, the environment temperature under which
the battery near the first thermal breaker RT1 is located
relatively lower than the environment temperature under which the
other battery near the second thermal breaker RT2 is located. The
temperature capable of making the first thermal breaker RT1 broken
is 60 degrees centigrade, and the temperature capable of making the
second thermal breaker RT2 broken is 70 degrees centigrade.
[0014] Under the normal condition, the OUTPUT terminal of the
control circuit 1 outputs a low level signal to the protective
circuit. On the contrary, if the temperature of any battery rises
to cause the corresponding thermal breaker RT1/RT2 broken due to
the overcharging/over-discharging, then the OUTPUT terminal will
output a high level signal to the protective circuit. For example,
if the temperature of the battery near the first thermal breaker
RT1 rises to 60 degrees centigrade on account of the overcharging
or over-discharging, then the first thermal breaker RT1 will be
broken that causes the high level signal output by the OUTPUT
terminal of the control circuit 1. Then, the protective circuit
interrupts the charging/discharging of the battery in the case
where the high level signal is received by the protective circuit
so as to protect the battery. The working rule of the second
thermal breaker RT2 is the same with the first thermal breaker RT1,
so it is not gone into details any more here.
[0015] As described above, the control circuit 1 of the present
invention protects the batteries by way of the thermal breakers
RT1, RT2, instead of thermistors T1, T2 and comparators U1, U2 of
the related art. Therefore, the control circuit 1 of the present
invention is relatively simpler and occupies a relatively smaller
space so that can meet the demand of both miniaturization and low
cost of electronic products.
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